System General Corporation

Chung-Hui Yeh

Pei-Sheng Tsu

Yi-Min Hsu

Ta-Yung Yang

Shih-Jen Yang

Ta-Hsu Huang

An angle detection apparatus for a rotor of a motor includes a period counter, a step period generator, and an angle generator. The period counter receives a rotor sensing signal, and calculates a plurality of time ranges of a plurality of pulses of the rotor sensing signal. The step period generator generates a ratio value and an error signal according to an average time range value of the time ranges and a set value. The step period generator further adjusts the ratio value according to the error signal, and generates a step time according to the adjusted ratio value and the average time range value. The angle generator receives the step time and the rotor sensing signal, and obtains an angle detection result according to the rotor sensing signal and the step time.

Angle detection apparatus and method for rotor of motor

A speed-control circuit for a BLDC motor is provided. The speed-control circuit includes a pulse generator, a current source circuit, a filter circuit, an error amplification circuit and a PWM circuit. The pulse generator detects a speed signal of the BLDC motor to generate a pulse signal. The filter circuit is coupled to the current source circuit to generate an average signal. The error amplification circuit receives the average signal and a speed-reference signal for generating a speed-control signal. The PWM circuit generates a switching signal to drive the BLDC motor in response to the speed-control signal. A pulse width of the switching signal is determined by the speed-control signal.

Constant-speed control circuit for BLDC motors

A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit determines the maximum torque and the maximum speed of the BLDC motor. The control circuit includes an over-current detection circuit to generate a reset signal in response to a switching current of the BLDC motor. The reset signal is generated when the switching current of the BLDC motor exceeds a threshold. A pulse width of the PWM signal is correlated to the level of a speed-control signal and the level of the torque-control signal. The pulse width of the PWM signal is also controlled by the reset signal generated by the over-current detection circuit.

Control circuit for BLDC motors

A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit comprises a speed-feedback loop and a torque-feedback loop to control the maximum speed and the maximum torque of the BLDC motor in parallel configuration. The speed-feedback loop generates a speed-control signal. The torque-feedback loop generates a torque-control signal. A PWM circuit receives the speed-control signal and the torque-control signal to generate a PWM signal. A pulse width of the PWM signal is correlated to the level of the speed-control signal and/or the level of the torque-control signal.

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Taipei County, Taiwan

Chung-Hui Yeh